Sewing machine frame



Nov. 19, 1946. K. PERKINS ETAL SEWING MACHINE FRAME Filed Feb. 23, 1943 4 Sh6ets-Sheat l NOV. 19, 1946. p k N E 2,411,459

SEWING MACHINE FRAME Filed Feb. 23, 1943 4 Sheets-Sheet 2 and w a 8 2M qmog Nov. 19, 1946. K. PERKINS ETAL SEWING MACHINE FRAME 4 Sheets-Sheet Filed Feb. 23, 1945 1 Nov. 19, 1946. K. PERKINS EIAL 2,411,459

SEWING MACHINE FRAME Filed Feb. 23', 1945 4 Sheets-Sheet 4 m QM" m m m i a W 3 p N I 8 E E I mp n V I n N N n a 9 Patented Nov. 19, 1946 SEWING MACHINE FRAME Kenneth Perkins, Scotch Plains, N. J and Malcolm S. Park, Mount Kisco, N. Y., assignors to The Singer Manufacturing Company,

Elizabeth, N. 3., a corporation of New Jersey Application February 23, 1943, Serial No. 476,830

4 Claims.

This invention relates to sewing machines and more particularly to a new type of sewing machine frame which is constructed of a moldable plastic material.

The demand for an inexpensive lightweight sewing machine has heretofore never been effectively met, and today, with so much emphasis upon portability, the demand for a compact featherweight sewing machine has been felt more acutely by sewing machine manufacturers. In the pastmany attempts have been made to cope with this problem as evidenced by the many patents which disclose divers forms of sewing machines designed with that end in view. Of such machines there types which are characterized by the application of different types of materials used in the construction of the machine framesone such type being shown in U. S. Patent No. 2,009,998, granted to Ignatz Gonyk on August 6, 1935; another in U. S. Patent No. 2,063,841, granted to Herbert J. Goosman on December 8, 1936; and another shown in British Patent No. 419,916, granted to G. M. Pfaff, on March 12, 1934. By virtue of the particular materials selected and the mode of their use in these machine frames, each of these machines is lighter in weight than its cast iron counterpart. Cast iron has always been the standard material out of which sewing machine frames have been fashioned. However, certain advantageous characteristics inherent in the old cast iron type of machine had to be sacrificed in producing each of the above noted lightweight units.

For example, a machine having the two-part sheet metal casing within which the stitching mechanism is supported, as instanced in the Gonyk patent. supra, makes for a lightweight frame but such a frame does not possess the sound absorbing character of cast iron. Furthermore, such a sheet metal casing is not capable of rigidly supporting the stitching mechanism, and unless internal bracings are freely used the casing will resonate when the machine is operating at high speeds.

In the machine of the Goosman type wherein the frame is made of die-cast aluminum alloy, little machining is required for its production and the unit is relatively light in weight and possesses fair sound absorbing characteristics. However, the cost ofsuch die-cast frames is high as compared to the usual cast iron counterpart.

A machine of the type disclosed in the Pfaff patent comprises a metallic frame supporting the swing mechanism and this frame is covered by are three representative a two-part plastic housing. If cast iron is used to construct the supporting frame of such a machine a relatively heavy unit will result and little advantage will be realized over the usual type of sewing machine. If, on the other hand, a lightweight aluminum alloy is used the expense of the unit will approach that of the above noted Goosman unit. Furthermore, as in the Gonyk construction, extreme care must be taken in the building of the machine to insure that the two-part casing is well braced so that it will not be subject to undue vibration. i

It is therefore, the chief object of the present invention to make it possible to retain all of the advantageous features of a cast iron framed sewing machine but at the same time produce an inexpensive and lightweight machine with a view to eliminating as many as possible of the disadvantages heretofore experienced in the application of such lightweight units;

Another object of the present invention is to provide a sewing machine frame which will require a minimum amount of machining operations in its manufacture, thus keeping the manufacturing expense thereof at a minimum.

A further object of this invention is the provision of a sewing machine frame of a lightweight material having high impact strength and a modulusof elasticity which is low so that the material will readily absorb the vibrations set up by the rapidlymoving sewing mechanism.

Still another object of the present invention is to provide a sewing machine frame of a molded resinous material, which frame is so constructed that any initial shrinkage that occurs therein will be controlled to the degree that no 'warpage of the frame will result therefrom.

The foregoing objects, and others ancillary thereto, have been attained by the provision of an improved sewing machine frame comprising a bed portion, a bracket-arm and standard unit, and an arm side cover-plate, all of said component parts being molded of a resinous material. It is, of course, not new to fashion certain portions of a sewing machine out of resinous materials as evidenced by the British Patent No. 419,916, granted to G. M. Pfaff on March 12, 1934, and the U. S. Patent No. 1,961,993, granted to C. S. Thompson on June 5, 1934- However, such resinous materials as were heretofore used on sewing machine parts were not adapted to be formed into an entire frame as they were lowstrength materials havinggreat moldability but rather poor mechanical properties.

The applicants have found that if they mold their frame of a base material having long fibers therein the resulting product will possess a relatively high impact strength. By properly molding such a long fibered base material the orientation of the fibers will not be uniform but they will mat or interlockwith each other in all directions thus imparting tremendous strength to the sewing machine frame. In a preferred form of the invention unground wood fibers or paper making stocks are used as a base material in preference to a ground wood flour or the like substance.

To properly bind these long matted fibers into a hardened mass a suitable content of resin is mixed with the fibers prior to the molding of the same. Any resin may be used without departing from the principle and scope of the invention, but we prefer to use a liquid synthetic resin of the heat hardening type, such as a phenol-formaldehyde resin, rather than a resin of the thermo-plastic type.

However, resins of a thermo-plasti'c nature maybe used if desired.

A preferred manner of forming the present sewing machine frame is to mix the fibers in the form-of a wet pulpwith liquid resin, felt the same upon a suitable die, abstract'the water fromthe matted mass, and thereafter mold the same under sufficient heat and pressure to form an infusible hardened product. The felting or preforming of the wet resin-impregnated pulp results in a preformed unit roughly the shape of the finished article. Upon drying this preformed unitit is readyto be placedbetween the molding dies which will, upon application of heat and presstne, produce the finished article.

I It is to be understood that in'the usual process of hot molding, the material which is placed between the dies is required to flow, under pressure of the dies, into its "final shape. This flow of the material under pressure of the dies is deleterious to a long fibrous material as it breaks or separatesthe fibers whereverthe flow occurs, with the result that the finished article is weak. Therefore, by preforming the pulp, as above described, a, stronger unit will result as less flow will be necessary in order to make the pulp conform to the shape of the molding dies. This is a particularly important consideration in the forming of the bracket-arm and standard unit of the present machine as it is of a rather intricate shape and would, if improperly molded, require much flowing of the pulp before it could be rendered infusi'ble under heat and pressure. Color may be imparted to the product by the addition of the proper pigments to the above noted solution.

For a more complete understanding of this type of molding process reference may be had to Patent No. 368,794, August 23, 1887, to Tobey, andPatentNo. 1,160,362, November 16, 1915, to Baekeland.

The "resulting product has a relatively lowperiod of vibration, and, therefore, makes for a sound-absorbing sewing machine frame.

The invention both in structure and'in operation, aswell as ancillary objects thereof, will be best understood from the following description taken in conjunction with the accompanying drawings in which:

Fig. .1 is a perspective view of the front side of the improved sewing machine with the arm side cover-plate removed.

Fig, 2'is a bottom plan view of the present machine.

lar shaped base or bed,

right standard l'i which carries Fig. 3 is a front side elevation of the machine.

Fig. 4 is a perspective view of the inside face of the arm side cover-plate.

Fig. 5 is a vertical section of the arm side coverplate taken substantially along line 5-5 of Fig. 4.

Fig. 6 is a horizontal section taken substantially along line -E-6 of Fig. 3.

Fig. '7 is a transverse vertical section taken substantially along line of Fig. 3.

Fig. 3 is a transverse vertical section taken substantially along line 8-8 of Fig. 3.

As illustrated in the drawings the sewing machine frame comprises a substantially rectanguindicated generally as Ill, having a work-supporting plate ll provided on its under face with a grid of strengthening ribs -l2, downwardly extending side-walls l3 and I4, and an end-wall [E'WhiCh connects the sidewalls I3 and I4.

Fixed to the bed Ill by the screws I6 is an upthe overhanging bracket-arm l8 terminating ina hollow needlebar mechanism compartment l9 carrying the usual reciprocatory needle-bar 2B, needle 21, presser-bar 22 and presser-foot 23. Disposed within and lengthwise of the overhanging bracket-arm i8 is the sewing machine main shaft or needle-bar actuating shaft'24 having a balance-wheel 25 fixed "thereto and adapted "to'be driven by a belt, not shown herein, which may be received within the belt-groove 26 of the balance-wheel. The forward endof the shaft 24 carries a crank 21 connected "by a pitman128 "with the needle-bar 2G for the purpose of reciprocating the same. The crank '21 is also connectedby means of a link 29 to the usual needle-thread take-up member 39 which in turn is pivotally secured to one end of a guide'link 3i the other'ehd of which is pivoted to the machine frame'at'point Mounted upon the shaft 24 is a bevel'gear -33 meshing with a similar gear 34 mounted upon the upper end of a vertical rotary or loop-taker actuating shaft 35'which is journaled' inthe upright standard ll. Secured upon the lower end portion of the shaft 35 is a crank disk 36 upon w'hicl'i a pin s1 is eccentrically mounted for the purpose of pivotally engaging and actuating one end of an oscillatory hook-driving pitman 38. The other end of the pitman 33 is pivotallyconnected to an arm "39 which actuates the rocking hook-shaft 59 in the usual manner. Upon the upper end of the vertical hook-shaft. issecured an oscillatory hook or loop-taker 4| which cooperates in the normal fashion with the needle 2! in the formation of stitches. V

A feed-bar 42 carrying a feed-dog E3 is'reciprrocated horizontally by a rocking feed-shaft '44, having at its rear'end an arm 45 to'which is pivotally connected the lowerend of a feed fork 45 operated from a cam or eccentric 41 o'n'the shaft 2d The length of the feed-dog movements in the horizontal direction may beadjusted by means of the usual adjusting lever 48 and its accompanying mechanism. The vertical movements of thefeed-bar are imparted thereto from abar 49 which is actuatedby means of the hookdriving mechanism. The rock-shaft 44 is "supported on pivot-lugs'sll and 5| threaded respec-- tively into the bearing supports 52 and 53 wh-ich V are formed integrally with'the bed Ill.

' For a more complete disclosure of the above described sewing machine feeding and st-itcldi'ng' mechanisms reference may be had to the U E'S.

Patent No. 663,696, to Diehl et al., dated Decemberll, 1900. i r

In the present form of the invention all of the moving elements and a majority of the remaining elements of the feeding and stitch-forming mechanisms are journaled or held Within the plastic frame by means. of metallic bushings. Figs. 3, 7 and 8-best illustrate the use of such metallic bushings. For example, the rotary main shaft 24 is journaled directly in bushings 54 and 55; the vertical hook-actuating shaft 35 is journaled in upper and lower bushings 58 and 51; the needle-bar 20 is vertically slidable in bushing 58; and the presser-bar 22 vertically slidable in bushing 59. All of these bushings maybe press-fitted into place after the frame has been completely molded, but if desired the bushings may be inserted into the preformed mat and have, in effect, the frame molded thereabout.

As hereinabove noted, the present frame comprises three separately molded parts, namely, the bed unit III, the standard and bracket-arm unit I! and I8, and the arm side cover-plate 60, which latter unit is adapted to be secured by screws 6| to the open sided standard and bracket-arm unit I! and H3. The standard and bracket-arm unit, or gooseneck, is formed as an open L-shaped trough and as best seen from Figs. 6 and 8 it is substantially C-shaped in cross section, In order to impart the this gooseneck the portion 62 of the gooseneck head, which is normally called a sewing machine face-plate, is formed integrally therewith, thus forming a trough-like unit bounded by continuous and substantially unbroken sidewalls on all sides including the ends at the head and base. In this connection it is to be noted that even the bottom portion of the gooseneck is closed as at 63.

To further strengthen the gooseneck and to prevent uneven shrinkage therein during the curing period thereof, there is provided within the hollow portion of the bracket-arm a plurality of intersecting or web-like interlocking concave ribs 64, and within the hollow standard portion, the vertical rib 65 and the horizontal concave ribs 66. The enlarged apertured lugs or webs 6'! and 68 form bearing blocks for a respective one of the shafts 24 and 35.

As may be seen from Fig. 1, the enlarged lugs 67 and 68 form with the unbroken side wall of the gooseneck and rib 65, three separate comparts within the confines of the trough. Also it may be seen that the needle-bar actuating means, including the crank 21 and link 28 are entirely disposed within that compartment defined by the end-closure plate 62 and the transverse lug 6'! which is formed at the juncture of the head l9 and the bracket-arm I8.

As also hereinabove noted the bed or base If] is formed with a plurality of intersecting ree forcing ribs [2 projecting from the bottom face thereof, as well as the downwardly extending side Walls l3 and I4 and the end wall l5. As may be best seen from Figs. 2 and 7 the side Walls 13 and I4 extend about the left-hand end of the base to form a boss 69 in which the hook-shaft 40 is journ-aled. As these side and end walls, ribs, and flanges as well as the boss are all molded to size in the above noted molding process, little if any machining is required in the manufacture of this base Ill.

The arm-side cover-plate 60 is provided with a bead upon the marginal portion of the inner face thereof, which bead mates with the groove maximum amount of strength to It provided aboutthe marginal portion of the gooseneck. Thus when the cover-plate 60 is positioned and secured in its proper place it lends added rigidity to the frame. The usual type of needlethread tension device 12 may be mounted upon the cover-plate 60, and further, the latter element may be slotted as at 13, M, 15 and 76 to permit various elements of the sewing machine mechanism to protrude therethrough.

By thus molding each of the three component parts of this sewing machine frame of a long fibered base substance bonded by means of a resinous material, a product is formed having great impact strength because of the orientation of its fibrous structure. Further, the finished article has a polished appearance due to presence of the heat-hardenable resin. Although this molded frame is of sufiicient hardness to withstand normal bending stresses, its modulus of elasticity is low enough to enable it to absorb a great amount of vibration. Also, as hereinabove noted, the novel bracing of the gooseneck, namely the use of the intersecting ribs and the troughlike outline thereof, imparts great strength to the frame as well as an ability to withstand an initial shrinkage without any accompanying warpage.

Having thus set forth the nature of the invention what we claim herein is:

1. 'A sewing machine gooseneck comprising a substantially L-shaped molded unit of a hard fibrous composition having an intermatted fibrous structure bound by a fused resin uniformly distributed throughout the unit, said gooseneck being bounded by continuous and substantially unbroken side walls on all sides, including the ends at the head and base, and excepting the front thereby to form a trough shaped structure having a substantially C-shaped transverse cross-section, a plurality of spaced apertured lugs molded integrally with said unit thereby to divide said trough into a plurality of separate compartments, a plurality of web-like ribs formed within said trough between said apertured lugs, and a coverplate removably secured to said side walls thereby to enclose said trough.

2. A sewing machine comprising a substantially fiat work-supporting bed, a loop-taker and loop-taker actuating means carried beneath said bed, an L-shaped gooseneck mounted upon said bed and formed of a hard fibrous composition comprising an intermatted fibrous structure bound by a fused resin, said gooseneck being bounded by continuous and substantially unbroken side walls on all sides, including the ends at the head and base, and excepting the front thereby to form an open-sided trough, a plurality of Web-like reinforcing ribs formed within and throughout the length of said trough, a plurality of spaced bearing supports molded integrally with and disposed Within said trough, a main shaft disposed Within said trough and journaled in at least one of said bearing supports, a reciprocatory needle-bar, and needle-bar actuating means including a needle-bar crank and link, said last mentioned means being operatively connected to said main shaft and being entirely disposed within said trough.

3. A sewing machine comprising a work-supporting bed unit, a loop-taker and loop-taker actuating means carried beneath said bed unit, a ooseneck mounted upon said bed unit, said gooseneck being molded of a hard fibrous composition comprising an intermatted fibrous structure bound by a fused resin, said gooseneck being bounded by continuous and substantially un- 7 8 broken sidewalls on all sides, including the ends a trough-shaped structure having asubstar tially at the head'and base, and excepting the front C-shaped transverse cross-section, themarginal thereby to form a trough-shaped structure hav- 7 portion of said gooseneck being provided along ing a substantially C-shaped transverse cross secthe major portion thereof with a groove, a coveri n, a plurality of spaced apertured lugs molded 5 plate provided with a marginal bead and being integrally with said gooseneck thereby to divide removably secured on said side walls with said said trough into a plurality of separate compartbeadand said groove in mating registration a ments, a plurality of concave interlocked ribs plurality of spaced apertured lugs integrally molded'between said apertured lugs, a main shaft formed within said trough thereby to divide the journaled in at least one of said apertured lugs 10 trough into a plurality of compartments, and a and being disposed within said trough, a needleplurality of concave interlocked ribs formed withbar, needle-bar actuating means including a in said trough and disposed between said apercrank and link carried at one end of said main tured ribs, said gooseneck and said cover-plate shaft and being entirely disposed within one of each comprising a body of material containing said compartments, and a cover-plate removab-ly 15 long-fibers intimately mixed within a resinous secured to said side walls thereby entirely to enbinder and compressed and hardened to its final =close said trough. iorm under heat and mechanical pressure; said 4. A sewing machine gooseneck, comprising, a long fibers being uniformly distributed throughsubstantially L-shaped unit, bounded by continu out the product but having an interlocked orious and substantially unbroken side walls on all 20 entation therein. I A 5 sides, including the ends at the head and base KENNETH PER/Knits. thereof, and excepting the front thereby forming 'MALCOLM S. PARK, 

